%0 Journal Article
%T Rex1/Zfp42 is dispensable for pluripotency in mouse ES cells
%A Shinji Masui
%A Satoshi Ohtsuka
%A Rika Yagi
%A Kadue Takahashi
%A Minoru SH Ko
%A Hitoshi Niwa
%J BMC Developmental Biology
%D 2008
%I BioMed Central
%R 10.1186/1471-213x-8-45
%X We showed the function of Rex1 in mouse ES cells as well as in embryos using the conventional gene targeting strategy. Our results clearly indicated that Rex1 function is dispensable for both the maintenance of pluripotency in ES cells and the development of embryos. However, Rex1-/- ES cells showed the defect to induce a subset of the marker genes of visceral endoderm, when differentiated as embryoid body, as found in EC cells.Rex1 should be regarded just as a marker of pluripotency without functional significance like the activity of alkaline phosphatase.Pluripotency is the differentiation ability of a cell to give rise all embryonic and adult cell types. Studies of embryonic stem (ES) cells have revealed molecular mechanisms that govern pluripotency involving in both genetic and epigenetic mechanisms [1,2]. Three transcription factors Oct3/4, Sox2 and Nanog are regarded as pivotal regulators because the loss-of-function experiments confirmed their essential functions for maintenance of pluripotency in ES cells as well as in peri-implantation development [3-7]. Moreover, the gain-of-function experiments emphasize their function associated to pluripotency. Nanog overexpression supports self-renewal of mouse ES cells in the absence of leukemia inhibitory factor (LIF) and promote imposition of pluripotency on somatic cells after cell-fusion with ES cells [8,9], whereas ectopic expression of Oct3/4 and Sox2 with additional two transcription factors Klf4 and cMyc is sufficient to induce pluripotency in embryonic and adult fibroblast cells [10]. Oct3/4 co-operates with Sox2 to activate transcription of the target genes including Oct3/4 [11], Sox2 [12] and Nanog [13]. It has been recently shown that Sox2 is essential to maintain expression of Oct3/4 in ES cells [7], suggesting that these three transcription factors form a network to maintain pluripotency.In addition to Oct3/4, Sox2 and Nanog, other putative transcription factors expressing pluripotent stem cells in stem-
%U http://www.biomedcentral.com/1471-213X/8/45